EPR hyperfine structure of F‐type centres in pure LiBaF₃ crystal

Abstract

We studied EPR spectra of pure LiBaF3 sample of high quality. For EPR measurements LiBaF3 sample was X‐irradiated at room temperature, however spectra could be observed at low temperatures ‐ at 77 K. All hyperfine structure lines of F‐type centre could be well resolved contrary to our earlier studies of Fe doped LiBaF3 crystal. Qualitative analysis with g‐tensor parameters derived from magneto‐optical measurements showed that the F‐type centre observed earlier by MCD‐EPR techniques is the same F‐type centre we observe with the EPR. We analyse origin of the hyperfine structure of the EPR spectra and their angular dependencies and discuss the structure of F‐type centres in the LiBaF3 crystal. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Epr Hyperfine Structure Of Radiation Defect In Oxyfluoride Glass Ceramics/ Radiācijas Defekta Epr Hipersīkstruktūra Oksifluorīdu Stikla Keramikā

“…12 to 14 equidistant EPR HF lines could be observed. A similar hyperfine structure with a large number of hyperfine lines was observed earlier for the F-centres in LiF [3] and LiBaF 3 [4] crystals, leading us to the conclusion that in glass-ceramics we also observe the EPR of F-centres.…”

“…Recently, F-centre as a radiation defect in fluorine crystals has been studied in detail in [3] for LiBaF 3 crystals and in [4] for LiYF 3 crystals. At the same time, no reports could be found on the resolved hyperfine (HF) structure of the EPR spectra of F-centres in the disordered structures like oxyfluoride glass and oxyfluoride glass ceramics.…”

Europium and Sodium Codoped LiCaAlF$_{6}$ Scintillator for Neutron Detection

“…It is yet worth noting that the hole transport in the LiCAF lattice is likely troubled due to the Li overstoichiometry in the growth process 15) and the existence of Li Ca antisite defects and/or Ca vacancies, which can be active deep hole traps analogously to LiBaF 3 . 22,23) In conclusion, we report a considerable enhancement of the neutron detection efficiency in the LiCAF:Eu scintillator due to the Na codoping. An LY value of 40000 ph/n was achieved, which provides great practical prospectives for its usage in thermal neutron detection, further supported by its nonhygroscopicity and availability of big bulk crystals grown by the Czochralski technique.…”

Effect of an electron beam irradiation on optical and luminescence properties of LiBaAlF6 single crystals

“…Let us first mention the available data on the related LiBaF 3 crystal. The X-ray irradiation of LiBaF 3 leads also to the formation of the F-type color centers, which are the main radiation defect created by X-rays in LiBaF 3 at T = 293 K; this center manifests itself in electron paramagnetic resonance and has g-tensor with main axis along the [1 0 0] direction of the crystal [18,19]. The model of the center has been supported by magneto-optical studies of defects and recombination luminescence at 4.2 and 293 K [20].…”